外延雾表面研究及设备改善

外延雾表面是一种常见的外延缺陷表现形式,在外延淀积后的硅片上,经常出现密集分布的雾缺陷,在器件工艺中,雾缺陷的存在会影响工艺器件的产品性能,因此硅片上的雾缺陷也成为了衡量外延层质量的一项重要参数。随着设备的更新和工艺的改进,不同的外延设备及工艺加工条件仍会有外延"雾"片的产生,对产品加工造成了困扰。文章中简要介绍了外延过程中产生发雾的原因,以理论和实践相结合的方式对外延雾缺陷的产生过程进行了试验验证,并提出了解决方式,通过增加外延炉氮气吹扫装置,隔离了外延设备关键部位与环境气体的接触,能有效降低设备自身的吸潮情况,减少外延过程中雾缺陷的形成。

Epitaxial fog surface is a common fore1 of epitaxial defects. After epitaxial deposition on silicon wafers, dense distribution of fog defects often occurs. In the process of devices, the existence of fog defects will affect the product performance of process devices. Therefore, the fog defect on silicon wafer has become an important parameter to measure the quality of epitaxial layer. With the renewal of equipment and the improvement of technology, different epitaxial equipment and process conditions will still have the appearance of epitaxial ＂fog＂, which has caused problems to the product processing. In this paper, the causes of fog formation in epitaxial process are briefly introduced, and the experimental verification of the formation process of epitaxial fog defect is carried out by combining theory with practice, and the solution is put forward by adding nitrogen purge device to the epitaxial furnace. The contact between the key parts of epitaxial equipment and the ambient gas can effectively reduce the moisture absorption of the equipment itself and reduce the formation of fog defects in the epitaxial process.